Aeromotive's 07 Shelby GT500 - Aeromodular

"I told him to make life easy on himself and do a small-block Ford," Duttweiler says. "In the end though, power-wise there's no difference, and the heads flow as good as the average Yates head. Once you got over the modular stigma, it really turned out pretty good and easily made the power numbers. The only downside is that there are four cams instead of one, and 32 valves instead of 16, so assembly and labor time are increased."

Power for this Pro car starts with a Ford GT 5.4-liter supercar aluminum block that's been milled by VT Competition Engines (Lansing, Michigan) to accept a Darton Modular Integrated Deck. If you're not familiar with the Darton MID design, basically the cylinder walls of the block are milled out, leaving an open rectangular shape. The MID consists of interlocking metal cylinder sleeves that are precision fit into the block.

Once that was complete, the block was filled with Hardblock, a concrete type of mixture that solidifies once it is poured in. Duttweiler says this was done mainly to prevent blown head gaskets from spewing water out of the side of the heads, which could possibly get under the tires. It also makes the block a lot more stable and less prone to distortion. Once the Hardblock has filled the block, the water passages are then welded up in the heads, and the only thing that the head gaskets have to deal with is cylinder pressure, which is easily accomplished. Duttweiler says that the small bore size of the modular engine family helps them seal better. Flatout Gaskets of Mundelein, Illinois, supplied the copper gaskets and O-rings that seal the heads to the block.

Once the GT block was worked over, it was filled with a destroked Kellogg crankshaft with a 3.75-inch stroke, MGP aluminum connecting rods, and JE pistons that fit the 3.70-inch bores. Displacement is now 323 ci, and when combined with the CNC-ported GT500 cylinder heads, provides a stout 11:1 compression ratio, which is possible thanks to the location of the spark plugs in the combustion chamber, as well as the use of 118-octane race fuel.

From the beginning of this project, Aeromotive's director of technology, Brett Clow, has been instrumental in numerous areas of the project.

"Brett has headed up our technical department for years, and when I decided to take on this project, I thought I'd give him a shot and see if he could manage this program, and we haven't looked back," Matusek says. "He managed the entire program, from turbos, to tuning, to engine assembly/maintenance and cylinder-head port design. I knew he was talented, but I didn't realize the extent. The project would have never gotten off the ground without him."

Noland's Head Service (Kansas City, Missouri) performed the valve job, cut the valve seats, and welded the coolant passages on the heads. Noland's was also charged with machining the cam tunnels to fit Babbitt-style bearings. These allow the cam to spin more freely at high rpm, and the reduced resistance also keeps the camshafts cooler. Knowing that hand porting each individual runner was going to take a lot of time, Matusek and Clow contacted Fox Lake Power Products in North Lawrence, Ohio, to port the heads on its CNC machine. After that, Clow installed the custom Ferrea valves and Comp Cams beehive valvesprings.

With the cylinder-head work complete, attention was turned toward camshaft selection, and the Aeromotive team really did its homework. Duttweiler is largely responsible for providing the specs, and with help from Comp Cams, the team has been very successful with some out-of-the-box designs.